[Xen-devel] [PATCH 1/2] xen: Drop XEN_DOMCTL_suppress_spurious_page_faults

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

This functionality is obsolete.  It was introduced by c/s 39407bed9c0 into
Xend, but never exposed in libxl.

While not explicitly limited to PV guests, this is PV-only by virtue of its
position in the pagefault handler.

Looking though the XenServer templates, this was used to work around bugs in
the 32bit RHEL/CentOS 4.{5..7} kernels (fixed in 4.8).  RHEL 4 as a major
version when out if support in 2017.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Ian Jackson <Ian.Jackson@xxxxxxxxxx>
CC: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
CC: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>
---
 tools/libxc/include/xenctrl.h       |  3 ---
 tools/libxc/xc_domain.c             | 12 ------------
 tools/python/xen/lowlevel/xc/xc.c   | 22 ----------------------
 xen/arch/x86/domctl.c               |  4 ----
 xen/arch/x86/traps.c                | 14 --------------
 xen/include/asm-x86/domain.h        |  3 ---
 xen/include/public/domctl.h         |  7 +------
 xen/xsm/flask/hooks.c               |  1 -
 xen/xsm/flask/policy/access_vectors |  3 +--
 9 files changed, 2 insertions(+), 67 deletions(-)

diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index 0ff6ed9e70..a36896034a 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -1787,9 +1787,6 @@ int xc_domain_set_machine_address_size(xc_interface *xch,
 int xc_domain_get_machine_address_size(xc_interface *xch,
                                       uint32_t domid);
 
-int xc_domain_suppress_spurious_page_faults(xc_interface *xch,
-                                         uint32_t domid);
-
 /* Set the target domain */
 int xc_domain_set_target(xc_interface *xch,
                          uint32_t domid,
diff --git a/tools/libxc/xc_domain.c b/tools/libxc/xc_domain.c
index 05d771f2ce..64ca513aae 100644
--- a/tools/libxc/xc_domain.c
+++ b/tools/libxc/xc_domain.c
@@ -2190,18 +2190,6 @@ int xc_domain_get_machine_address_size(xc_interface 
*xch, uint32_t domid)
     return rc == 0 ? domctl.u.address_size.size : rc;
 }
 
-int xc_domain_suppress_spurious_page_faults(xc_interface *xc, uint32_t domid)
-{
-    DECLARE_DOMCTL;
-
-    memset(&domctl, 0, sizeof(domctl));
-    domctl.domain = domid;
-    domctl.cmd    = XEN_DOMCTL_suppress_spurious_page_faults;
-
-    return do_domctl(xc, &domctl);
-
-}
-
 int xc_domain_debug_control(xc_interface *xc, uint32_t domid, uint32_t sop, 
uint32_t vcpu)
 {
     DECLARE_DOMCTL;
diff --git a/tools/python/xen/lowlevel/xc/xc.c 
b/tools/python/xen/lowlevel/xc/xc.c
index 188bfa34da..7e831a26a7 100644
--- a/tools/python/xen/lowlevel/xc/xc.c
+++ b/tools/python/xen/lowlevel/xc/xc.c
@@ -786,22 +786,6 @@ static PyObject 
*pyxc_dom_set_machine_address_size(XcObject *self,
     Py_INCREF(zero);
     return zero;
 }
-
-static PyObject *pyxc_dom_suppress_spurious_page_faults(XcObject *self,
-                                                     PyObject *args,
-                                                     PyObject *kwds)
-{
-    uint32_t dom;
-
-    if (!PyArg_ParseTuple(args, "i", &dom))
-       return NULL;
-
-    if (xc_domain_suppress_spurious_page_faults(self->xc_handle, dom) != 0)
-       return pyxc_error_to_exception(self->xc_handle);
-
-    Py_INCREF(zero);
-    return zero;
-}
 #endif /* __i386__ || __x86_64__ */
 
 static PyObject *pyxc_gnttab_hvm_seed(XcObject *self,
@@ -2436,12 +2420,6 @@ static PyMethodDef pyxc_methods[] = {
       "Set maximum machine address size for this domain.\n"
       " dom [int]: Identifier of domain.\n"
       " width [int]: Maximum machine address width.\n" },
-
-    { "domain_suppress_spurious_page_faults",
-      (PyCFunction)pyxc_dom_suppress_spurious_page_faults,
-      METH_VARARGS, "\n"
-      "Do not propagate spurious page faults to this guest.\n"
-      " dom [int]: Identifier of domain.\n" },
 #endif
 
     { "dom_set_memshr", 
diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index 2d45e5b8a8..34a6f88b8a 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -988,10 +988,6 @@ long arch_do_domctl(
         }
         break;
 
-    case XEN_DOMCTL_suppress_spurious_page_faults:
-        d->arch.suppress_spurious_page_faults = 1;
-        break;
-
 #ifdef CONFIG_HVM
     case XEN_DOMCTL_debug_op:
     {
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 23069e25ec..350903add5 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -1452,20 +1452,6 @@ void do_page_fault(struct cpu_user_regs *regs)
               error_code, _p(addr));
     }
 
-    if ( unlikely(current->domain->arch.suppress_spurious_page_faults) )
-    {
-        pf_type = spurious_page_fault(addr, regs);
-        if ( (pf_type == smep_fault) || (pf_type == smap_fault))
-        {
-            printk(XENLOG_G_ERR "%pv fatal SM%cP violation\n",
-                   current, (pf_type == smep_fault) ? 'E' : 'A');
-
-            domain_crash(current->domain);
-        }
-        if ( pf_type != real_fault )
-            return;
-    }
-
     if ( unlikely(regs->error_code & PFEC_reserved_bit) )
         reserved_bit_page_fault(addr, regs);
 
diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index 933b85901f..8523c3f5e0 100644
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -339,9 +339,6 @@ struct arch_domain
     /* Is shared-info page in 32-bit format? */
     bool_t has_32bit_shinfo;
 
-    /* Domain cannot handle spurious page faults? */
-    bool_t suppress_spurious_page_faults;
-
     /* Is PHYSDEVOP_eoi to automatically unmask the event channel? */
     bool_t auto_unmask;
 
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 19486d5e32..726ce675e8 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -698,11 +698,6 @@ struct xen_domctl_subscribe {
 /* XEN_DOMCTL_set_machine_address_size */
 /* XEN_DOMCTL_get_machine_address_size */
 
-/*
- * Do not inject spurious page faults into this domain.
- */
-/* XEN_DOMCTL_suppress_spurious_page_faults */
-
 /* XEN_DOMCTL_debug_op */
 #define XEN_DOMCTL_DEBUG_OP_SINGLE_STEP_OFF         0
 #define XEN_DOMCTL_DEBUG_OP_SINGLE_STEP_ON          1
@@ -1172,7 +1167,7 @@ struct xen_domctl {
 #define XEN_DOMCTL_get_device_group              50
 #define XEN_DOMCTL_set_machine_address_size      51
 #define XEN_DOMCTL_get_machine_address_size      52
-#define XEN_DOMCTL_suppress_spurious_page_faults 53
+/* #define XEN_DOMCTL_suppress_spurious_page_faults 53 - Obsolete */
 #define XEN_DOMCTL_debug_op                      54
 #define XEN_DOMCTL_gethvmcontext_partial         55
 #define XEN_DOMCTL_vm_event_op                   56
diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c
index 791c1f66af..fd5ec992cf 100644
--- a/xen/xsm/flask/hooks.c
+++ b/xen/xsm/flask/hooks.c
@@ -712,7 +712,6 @@ static int flask_domctl(struct domain *d, int cmd)
 
     case XEN_DOMCTL_subscribe:
     case XEN_DOMCTL_disable_migrate:
-    case XEN_DOMCTL_suppress_spurious_page_faults:
         return current_has_perm(d, SECCLASS_DOMAIN, DOMAIN__SET_MISC_INFO);
 
     case XEN_DOMCTL_set_virq_handler:
diff --git a/xen/xsm/flask/policy/access_vectors 
b/xen/xsm/flask/policy/access_vectors
index 194d743a71..c9ebd0f37e 100644
--- a/xen/xsm/flask/policy/access_vectors
+++ b/xen/xsm/flask/policy/access_vectors
@@ -176,8 +176,7 @@ class domain
     getpodtarget
 # XENMEM_set_pod_target
     setpodtarget
-# XEN_DOMCTL_subscribe, XEN_DOMCTL_disable_migrate,
-# XEN_DOMCTL_suppress_spurious_page_faults
+# XEN_DOMCTL_subscribe, XEN_DOMCTL_disable_migrate
     set_misc_info
 # XEN_DOMCTL_set_virq_handler
     set_virq_handler
-- 
2.11.0


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